1. Field of the Invention
The present invention relates to a rotodynamic pump which may be, for example, mobile.
2. Background
Liquids which contain a high proportion of solids, such as sludges, slurries, and fibrous and viscous liquids are particularly difficult to pump, especially when the material to be pumped has been standing for some time. Typically, such materials are stored in open lagoons and there is increasing environmental pressure to empty and clean these lagoons.
It is therefore an object of the present invention to provide a rotodynamic pump which is capable of pumping liquids containing a high proportion of solids.
According to the invention there is provided a rotodynamic pump comprising a centrifugal impeller provided within a volute body and an emulsifier provided in the region of an inlet of the volute body and rotatable with the centrifugal impeller for emulsifying material to be pumped.
The emulsifier may comprise a plurality of emulsifying blades extending in the axial direction of the centrifugal impeller and spaced laterally from the axis thereof. The emulsifying blades may be mounted on a base plate arranged at that end of the blades remote from the centrifugal impeller. The blades may have a hydrofoil shape or may be arcuate or straight and may be provided with a relatively sharp leading edge. The shape of the blades may depend upon the nature of the material to be pumped.
The pump may include an auger member rotatable with the centrifugal impeller and disposed in the region of the inlet of the volute body. The auger member may be positioned within the emulsifier.
The centrifugal impeller may incorporate a plurality of impeller blades, the blades being dimensioned to be shorter than the axial height of the volute body. The blades may be about half the axial height of the volute body.
The emulsifier may be positioned within a protective cage. The protective cage may comprise an annular ring positioned on that side of the emulsifier remote from the centrifugal impeller and secured to the volute body.
A plurality of nozzles for emollient injection may be provided around the emulsifier, for example intermediate the emulsifier and the protective cage. The nozzles may be directed in the axial direction. The nozzles may be secured to the underside of the volute body.
A stationary member may be positioned adjacent to the emulsifier for macerating the material to be pumped. The stationary member may comprise a plurality of stationary blades extending in the axial direction and spaced laterally of the axis, the stationary blades being positioned radially within the blades of the emulsifier. The stationary blades may be secured to the volute body. The stationary blades may have a hydrofoil shape or may be arcuate or straight. The shape of the blades may depend upon the nature of the material being pumped. The radially outer end of each stationary blade may be relatively sharp for co-operation with the blades of the emulsifier.